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Trying to get the XV-11 Lidar to work

asked 2014-10-14 16:18:28 -0500

tinytron gravatar image

Hey there!

I already asked this over at the Trossen Robotics Forum but did not get a reply yet. Maybe someone here can give me a hint at what might be wrong with my XV-11 Lidar Setup.

I bought the laser scanner from Ebay and am trying to get it to work in ROS.

What I have done so far:

  • Connected the Lidar to ROS Indigo running Ubuntu in Virtualbox on a Windows Machine.

  • For the power to the motor I am using a 3V regulator that gets its power form USB (5V).

  • The sensor is powered by an Arduino with 3.3V for now.

  • Instead of the Sparkfun FTDI board I am using a standard RS-232 to USB Adapter that is getting its data from the Lidard's Tx. The adapter gets accepted by Ubuntu. Dmesg shows:

    usb 1-2: FTDI USB Serial Device converter now attached to ttyUSB0

  • Running

    rostopic echo /scan

I get this:


header: seq: 34 stamp: secs: 1413106818 nsecs: 470585788 frame_id: neato_laser angle_min: 0.0 angle_max: 6.28318548203 angle_increment: 0.0174532923847 time_increment: 0.00059940997744 scan_time: 0.0 range_min: 0.0599999986589 range_max: 5.0 ranges: [0.25600001215934753, 8.192000389099121, 4.928999900817871, 13.229000091552734, 13.300999641418457, 13.274999618530273, 10.946999549865723, 0.37700000405311584, 14.380999565124512, 15.883000373840332, 15.381999969482422, 0.25600001215934753, 8.960000038146973, 6.848999977111816, 13.114999771118164, 13.0649995803833, 13.126999855041504, 13.109000205993652, 0.36899998784065247, 14.380999565124512, 15.883000373840332, 15.378000259399414, 0.5120000243186951, 1.2799999713897705, 6.880000114440918, 13.14900016784668, 10.869000434875488, 9.96500015258789, 10.836999893188477, 0.37599998712539673, 14.348999977111816, 15.873000144958496, 15.847999572753906, 16.128000259399414, 11.008000373840332, 6.90500020980835, 11.003000259399414, 10.888999938964844, 10.954999923706055, 4.479000091552734, 0.33799999952316284, 15.279000282287598, 14.972999572753906, 7.293000221252441, 0.23399999737739563, 8.019000053405762, 8.29699993133545, 15.732999801635742, 15.833000183105469, 7.519999980926514, 11.776000022888184, 8.960000038146973, 6.888999938964844, 11.795000076293945, 13.74899959564209, 13.708999633789062, 11.914999961853027, 0.4320000112056732, 11.229000091552734, 16.277000427246094, 16.277000427246094, 9.472000122070312, 8.704000473022461, 3.884999990463257, 16.381999969482422, 16.381999969482422, 16.381999969482422, 16.381999969482422, 8.295999526977539, 15.189000129699707, 16.277000427246094, 13.991999626159668, 9.472000122070312, 0.0, 3.628000020980835, 16.381999969482422, 16.381999969482422, 16.381999969482422, 16.381999969482422, 7.690999984741211, 15.189000129699707, 16.277000427246094, 15.187999725341797, 9.472000122070312, 7.935999870300293, 3.627000093460083, 16.381999969482422, 16.381999969482422, 16.381999969482422, 16.381999969482422, 8.399999618530273, 15.189000129699707, 16.277000427246094, 13.991999626159668, 9.472000122070312, 7.679999828338623, 3.625999927520752, 16.381999969482422, 16.381999969482422, 16.381999969482422, 16.381999969482422, 8.295999526977539, 15.189000129699707, 16.277000427246094, 13.991999626159668, 9.472000122070312, 7.423999786376953, 13.097000122070312, 16.381999969482422, 16.381999969482422, 16.381999969482422, 16.381999969482422, 8.406000137329102, 15.189000129699707, 16.277000427246094, 16.37700080871582, 15.871999740600586, 11.520000457763672, 14.026000022888184, 16.381999969482422, 16.381999969482422, 16.381999969482422, 16.381999969482422, 0.43700000643730164, 16.35700035095215, 16.37700080871582, 16.356000900268555, 15.871999740600586, 4.0960001945495605, 14.001999855041504, 16.381999969482422, 16.381999969482422, 16.381999969482422, 16.381999969482422, 0.43700000643730164, 16.047000885009766, 16.37700080871582, 16.327999114990234, 15.871999740600586, 8.192000389099121,

and so on...

So there seems to be data coming in.

But then here's my problem. In RVIZ the data looks like noise and it seems like the Laser is detecting ...

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answered 2014-10-15 01:32:30 -0500

ahendrix gravatar image

The header is generated on the computer side, not the lidar, so it's quite possible that your data is corrupt even though the header looks correct. TTL and RS-232 use different voltages and different polarities, so that's probably causing problems.

I would start by finding a proper USB to TTL serial converter. It doesn't have to be the specific Sparkfun model, but it should definitely be a 5V level and non-inverted (RS-232 is inverted).

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answered 2014-10-15 02:05:32 -0500

tinytron gravatar image

updated 2014-11-18 10:35:26 -0500

Hey ahendrix,

thanks for the quick response!

I noticed before that connecting the Lidar's Tx to the RS232 Rx did not deliver any data. So I connected Tx to Tx on the RS232 plug, which seems kinda fishy.

I ordered a XV-11 controller from GetSurreal now and it's on its way. I'll update this post as soon as I have tested it.

Thanks again.

EDIT:

The issue is resolved and the XV-11 is working beautifully with ROS and hector_slam.

There were a couple of things I had to change. First the Serial converter, I am now using a FTDI Breakout from Sparkfun to translate the signal to USB. Obviously these RS-232 converters speak a different language and that messed up the signal.

Then I switched the sensor power from 3.3V to 5V. On the inside of the XV-11 on the board it says 5V right next to the power cable.

Next I want to add the Razor 9dof IMU to the setup to get some attitude data, will see how that goes...

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Asked: 2014-10-14 16:17:50 -0500

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Last updated: Nov 18 '14